During the past two decades there has been a rapid proliferation of portable devices such as cell phones, pagers, laptop computers, CD and DVD players, and the like. Such portable devices typically depend upon batteries of some sort for their energy requirements and the operating duration of the devices is thus governed by the available energy, which in turn is affected by the rate at which the available energy is used or depleted. There has also been an increased awareness of the need to increase energy efficiency in non-portable devices. For example, the United States government has an “Energy Star” program which helps businesses and individuals protect the environment through superior energy efficiency. See [http://]www.energystar.gov
In order to conserve electricity, or to extend battery life, e.g., in laptop computer systems, various power-saving methods are used. These may include monitor timeouts, hard disk spin downs, and the computer entering a “sleep” state after a period of inactivity. On certain processor systems, it is also possible to adjust the operating clock frequency, or internal operating voltage, of the central processing unit (CPU). When the processor runs at slower clock speeds, or lower voltages, it requires less power. As a significant amount of power is consumed by the CPU, reducing clock speeds and voltages is a reasonable strategy to extend operational time when running off a battery. For many of the most common applications, a CPU running at a reduced speed is usually sufficiently fast to not incur any inconvenience for the user.
The current method used to set the power saving modes of a computer or other device involves accessing a power management program. This program may be accessed through a BIOS (Basic Input Output System) setup program, through the operating system, or through an interface. In any case, to efficiently utilize and conserve power under various operating conditions, the user must set appropriate power-saving parameters. As most people do not enjoy adjusting such system internals, they tend to set the processor speed to its highest value and leave it at that. On laptop systems, this can cause an unnecessary loss of battery time.
Furthermore, current laptop power management schemes or parameters typically rely upon timeout values or on explicit user input to initiation transition into lower power modes. A drawback of this method is that this is not optimal for power management. In many cases the user may just walk away from the machine and not want to bother with the hassle to manually initiate a transition to a low power state. Using timeout values, i.e., detecting that there is no activity on the keyboard, mouse, or other input device, for a preselected amount of time, and go to the lower power state has the problem that user typically set large timeout values. Users do this because they do not want this machine to go into low power state sometimes because they may doing something else while near the computer or other device but want the display screen to be active; this may be the case because the user would like to see information from automatic software agents, such as stock tickers, instant messages, etc., that may be displayed even if there is no user activity on the keyboard, mouse, or other input device. Alternatively, a user may be playing some media, such as an audio file, movie file, DVD movie, or the like, where it is unlikely there is any activity on the keyboard, mouse, or other input device. In addition, when a user is making a screen show presentation it is unlikely there is anything other than occasional activity on the keyboard, mouse, or other input device.